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        검색결과 220

        101.
        2010.10 구독 인증기관·개인회원 무료
        The two related species in the tribe Archipini, Adoxophyes paraorana and Pandemis heparana (Lepidoptera: Tortricidae), are insect pests of fruit trees in Korea. We investigated differences in pheromone system and seasonal flight of these two species. GC-MS analyses of pheromone gland extracts revealed that females of both species produce blends of Z11-14:OAc, Z9-14:OAc, and Z11-14:OH in similar ratios. The average ratio of three components in extracts was estimated to be 3:100:0.3 for A. paraorana and 3:100:2 for P. heparana. Field tests showed that Z11-14:OAc and Z9-14:OAc were essential for attraction of A. paraorana males and the presence of Z11-14:OH in primary binary blend did not induce any synergistic or inhibitory effect. For the attraction of P. heparana males, however, all three components, Z11-14:OAc, Z9-14:OAc and Z11-14:OH, were indispensable. These results suggest that male A. paraorana do not discriminate between conspecific females and those of P. heparana in the field. Comparison of the flight phenologies in apple and pear orchards showed that the two species are sympatric and overlap in flight periods. This finding eliminates pheromone specificity and seasonal separation as premating reproductive isolation mechanism between A. paraorana and P. heparana.
        102.
        2010.05 구독 인증기관·개인회원 무료
        Our previous study demonstrated that Coprisin, a peptide from Copris tripartitus infected with bacterial pathogens, has an antibacterial activity. We assessed in this study whether Coprisin caused cellular toxicity in various mammalian cell lines. Coprisin selectively caused a marked drop of cell viability in Jurkat T cells, U937 cells and AML-2 cells belonging to the human leukemia cells but not in Caki cells and Hela cells. Fragmentation of DNA, a maker of apoptosis, was also confirmed in theleukemia cell lines but not in other cells. The Coprisin-induced apoptosis in leukemia cells was mediated by AIF (apoptosis inducing factor), a caspase -independent pathway.
        103.
        2010.05 구독 인증기관·개인회원 무료
        Synanthedon haitangvora (Lepidoptera: Sesiidae) is an economically important pest of apple trees in Korea and China. We report here the identification of compounds in pheromone gland extracts of female S. haitangvora, and the male responses to blends of different components and ratios in the field. Two major components from pheromone gland extracts of S. haitangvora females were identified as Z3,Z13-18:OAc and E2,Z13-18:OAc, and the average ratio of these components was about 1:1. Seven minor components, Z9-16:OAc, Z11-16:OAc, Z9-18:OAc, Z13-18:OAc, E3,Z13-18:OAc, Z3,Z13-18:OH, and E2,Z13-18:OH, also were identified from gland extracts. Field tests showed that male S. haitangvora were attracted to Z3,Z13-18:OAc alone, but the maximum number of males was attracted to the binary blend of Z3,Z13-18:OAc and E2,Z13-18:OAc mimicking the blend found in female extracts. The addition of minor components to a 1:1 blend of Z3,Z13-18:OAc and E2,Z13-18:OAc did not increase the numbers of moths captured. The only significant effect of minor components was the strong inhibitory effect of adding Z3,Z13-18:OH to the primary binary blend. Increasing doses of the optimum pheromone blend in the lures from 0.1 to 2.0 mg increased trap catches of male S. haitangvora.
        104.
        2009.12 구독 인증기관 무료, 개인회원 유료
        Human mesenchymal stem cell (hMSCs) isolated from human adult bone marrow have self-renewal capacity and can differentiate into multiple cell types in vitro and in vivo. A number of studies have now demonstrated that MSCs can differentiate into various neuronal populations. Due to their autologous characteristics, replacement therapy using MSCs is considered to be safe and does not involve immunological complications. The basic helix-loop-helix (bHLH) transcription factor Olig2 is necessary for the specification of both oligodendrocytes and motor neurons during vertebrate embryogenesis. To develop an efficient method for inducing neuronal differentiation from MSCs, we attempted to optimize the culture conditions and combination with Olig2 gene overexpression. We observed neuron-like morphological changes in the hMSCs under these induction conditions and examined neuronal marker expression in these cells by RTPCR and immunocytochemistry. Our data demonstrate that the combination of Olig2 overexpression and neuron-specific conditioned medium facilitates the neuronal differentiation of hMSCs in vitro. These results will advance the development of an efficient stem cell-mediated cell therapy for human neurodegenerative diseases.
        4,000원
        105.
        2009.10 구독 인증기관·개인회원 무료
        COPRISIN is an antibiotic substance extracted from Copris tripartitus. This study is intended to identify various cell biological stimuli that COPRISIN, widely known as an antibacterial substance, has on human cells and to identify its molecule mechanism. A variety of human cell lines were divided into epithelial cells including kidney cells or womb cells, and immunocyte including T cells or macrophages and, after their being cultivated and maintained, cell biological changes of the respective cells according to COPRISIN treatment were compared. As a result, it was confirmed that, different from other experiment cells, COPRISIN specifically caused cell kill in T cells and macrophages. That is, fragmentation of DNA, typical characteristics observed in the process of apoptosis, was confirmed in the nucleus of cells dying owing to COPRISIN treatment. An Apoptosis process is one dependent upon activity of caspase family protein, it was proved that COPRISIN medium cell kill process was one through a caspase-independent route such as AIF. Though it was found out that transcription of TNF-α and extracellular TNF-α secretion increased in blood cells stimulated by COPRISIN, it was also confirmed that TNF-α was a major medium factor in a COPRISIN induced cell kill process from the fact that a cell kill process by COPRISIN was not inhibited at all with TNF-α inhibiting antibody treatment. Above results revealed that COPRISIN, different from other tissue origin cells including kidney cells, can specifically induce apoptosis in immunocyte, which is caused by a caspase-independent cell signal transmission route.
        109.
        2008.10 구독 인증기관·개인회원 무료
        We tested differences in female pheromone production and male response in three species of the genus Adoxophyes in Korea. Females of all three species produced mixtures of Z9-14:OAc and Z11-14:OAc as major components but in quite different ratios. The ratio of Z9-14:OAc and Z11-14:OAc in pheromone gland extracts was estimated to be 100:198 for A. honmai, 100:23 for A. orana, and 100:3880 for A. sp. Field tests showed that males of each species were preferentially attracted to the two-component blends of Z9-14:OAc and Z11-14:OAc mimicking the blends found in pheromone gland extracts of conspecific females. The effects of minor components identified in gland extracts on trap catches varied with species. Addition of 10me-12:OAc or E11-14:OAc to the binary blend of Z9-14:OAc and Z11-14:OAc significantly increased captures of A. honmai males, whereas E11-14:OAc exhibited a strongly antagonistic effect on catches of A. sp. males. Moreover, Z9-14:OH or Z11-14:OH added to the binary blends increased attraction of male A. orana but not A. honmai and A. sp. males, suggesting that these minor components, in addition to the relative ratios of the two major components, play a noteworthy role in reproductive isolation between Adoxophyes species in the southern and midwestern Korea where these species occur sympatrically.
        114.
        2005.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        방사성 폐기물 핵종 재고량 평가에 필요한 핵종분석을 위하여 다양한 매질의 방사성 폐기물 시료로부터 및 의 분리에 관한 연구가 수행되고 있다. Ni은 음이온교환 수지와 Sr-Spec 추출 크로마토그래피 수지로 Re(의 대용물), Nb, Fe 및 Sr을 차례로 분리하는 과정에서 Ca, Mg, Al, Cr, Ti, Mn, Ce, Na, K 및 Cu와 함께 회수되었다. 본 연구에서는 Ni의 선택적 분리기술을 확립하기 위하여 Ni-Spec 추출 크로마토그래피 및 양이온교환수지법으로 이들의 분리거동을 비교하였다. 또한 Ni의 정제와 기체비례계수법으로 방사능을 측정하기에 적합한 계측시료 준비를 위하여 ammonium 및 tartaric 에서 dimethylglyoxime(DMG)에 의한 Ni의 침전거동을 조사하였다 원자력발전소로부터 채취한 폐이온교환수지 시료 용해용액의 화학조성을 모사하여 만든 모의 폐이온교환수지 용액을 사용하여 Re, Nb, Fe 및 Sr 분리과정을 거쳐 최종적으로 분리한 Ni의 회수율은 이었다. 또한 tartaric 에서 DMG에 의한 Ni의 회수율은 이었다.
        4,000원
        115.
        2005.10 구독 인증기관·개인회원 무료
        116.
        2005.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present analysis results of the energy spectra of MCG-2-58-22 associated with occasional flares which appear in a long-term X-ray light curve. We measure an intrinsic power-law slope of this object to be Γ =1.74 ± 0.02 in the energy range of ~ 1 -5 keV and find that this slope is little affected by flares. We confirm that there exists a broad excess emission above 5 keV to the power-law continuum. The excess emission is less variable compared with a flux variation of flare and tends to be relatively weak during flares. A soft X-ray spectrum is also found to change, implying the presence of a variable soft component. We discuss the implications of these spectral variations.
        4,000원